1. Field of the Invention
The present invention relates to ink cartridges configured to store ink.
2. Description of Related Art
Known inkjet printers perform printing by ejecting ink from a print head onto a recording medium. Ink cartridges are often removably mounted to known inkjet printers. If a print head tries to eject ink from an empty ink cartridge, air may enter into the print head, which may lead to printing failures. Moreover, the print head can be ruined from the entry of air therein. To prevent such a situation, an ink level of an ink cartridge has to be constantly monitored in order to stop ink ejection from the print head before the ink cartridge is empty.
For example, a flat float having a lower density than ink may be disposed within an ink chamber of an ink cartridge. The position of the float changes according to the ink level in the ink chamber. Thus, it can be determined that cartridge is substantially empty of ink by detecting the position of the float.
In the known ink cartridge, the float may not lower as the ink level falls if the float sticks to an inner wall surface of the ink chamber. The surface tension of ink adhering to the inner surface of the ink cartridge, or some other disturbance, may cause the float to stick. Accordingly, an ink level of the ink cartridge may not be detected accurately.